Transitioning a video call between networks

ABSTRACT

A method for transitioning a video call is provided. The method can include a wireless communication device participating in a video call with a remote communication device via a first video call session established over a connection between the wireless communication device and a first cellular network. The video call can include a packet switched video stream carried over a first bearer and an audio stream carried over a second bearer. The method can further include the wireless communication device determining a degradation in a connection quality for the first cellular network; transitioning to a legacy cellular network having a circuit switched domain in response to the degradation in connection quality for the first cellular network; establishing a second video call session on the legacy cellular network; and using the second video call session to continue the video call on the legacy cellular network.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. ProvisionalPatent Application No. 61/745,454, filed on Dec. 21, 2012, which ishereby incorporated herein by reference in its entity.

FIELD

The described embodiments relate generally to wireless communications.More particularly, the present embodiments relate to transitioning avideo call between networks.

BACKGROUND

Many modern wireless communication devices include cameras enabling thedevices to support video calls, which can include both video and audio.These video calls can be established and supported over modern cellularnetworks, such as Long Term Evolution (LTE) networks, which can supportpacket switched data at a sufficient rate to support streaming video.LTE networks, which can support faster data rates than legacy cellulartechnologies, are being developed and deployed. However, LTE coverage isnot yet universal and, as such, LTE networks are being co-deployed inoverlapping regions with legacy cellular networks and wirelesscommunication devices may transition between cellular radio accesstechnologies (RATs) as a result of moving in and out of LTE coverage dueto device mobility.

In an instance in which a wireless communication device has an activesession, such as an active video call, when transitioning betweennetworks it can be important from a user perspective to transition thesession without dropping the session. However, some networks may notsupport inter-network session transitions. Thus, for example, activevideo calls can be dropped during some network transitions, resulting ina negative user experience.

SUMMARY

Some example embodiments disclosed herein provide for transitioning avideo call between networks. More particularly, some example embodimentsprovide a wireless communication device configured to proactivelyestablish a new video call session in response to transitioning betweennetworks which do not support network coordinated handover of the videocall session so that a video call can be continued on the new networkwithout the user having to manually initiate reestablishment of thevideo call. As such, while a user may notice a relatively brief pause inthe video call, the user may not be aware of a call drop, and does nothave to take action to proactively reestablish the video call followingnetwork transition. Some embodiments may be particularly advantageouswhen a device is transitioning from a network supporting packet switched(PS) transmission of voice, such as some LTE networks, to a legacycellular network, such as a third generation (3G) network, having acircuit switched (CS) domain in instances in which network coordinatedhandover of a video call session is not supported by the LTE networkand/or by the legacy cellular network.

This Summary is provided merely for purposes of summarizing some exampleembodiments so as to provide a basic understanding of some aspects ofthe disclosure. Accordingly, it will be appreciated that the abovedescribed example embodiments are merely examples and should not beconstrued to narrow the scope or spirit of the disclosure in any way.Other embodiments, aspects, and advantages will become apparent from thefollowing detailed description taken in conjunction with theaccompanying drawings which illustrate, by way of example, theprinciples of the described embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 illustrates a wireless communication system in accordance withsome example embodiments;

FIG. 2 illustrates a block diagram of an apparatus that can beimplemented on a wireless communication device in accordance with someexample embodiments;

FIG. 3 illustrates a flowchart of operations that can be performed by awireless communication device in accordance with an example method fortransitioning a video call to a legacy cellular network according tosome example embodiments;

FIG. 4 illustrates a flowchart of operations that can be performed by awireless communication device in accordance with another example methodfor transitioning a video call between networks according to someexample embodiments;

FIG. 5 illustrates a flowchart of operations that can be performed by awireless communication device in accordance with an example method forcontrolling user interface indications when transitioning a video callaccording to some example embodiments; and

FIG. 6 illustrates a flowchart of operations that can be performed by acommunication device in response to another device transitioning betweennetworks during a video call according to some example embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims.

Some example embodiments disclosed herein provide for transitioning avideo call between networks. In this regard, some example embodimentsprovide a wireless communication device configured to proactivelyestablish a new video call session in response to transitioning betweennetworks so that a video call can be continued on the new network, evenwhen network coordinated handover of the video call from the priornetwork to the new network is not supported. In accordance with somesuch example embodiments, a video call application that can beimplemented on the wireless communication device and/or on a remotecommunication device participating in the video call can be configuredto transition to the new video call session after the original videocall session has been terminated or dropped without alerting the userthat the original video call session has been dropped or that a newvideo call session has been established. As such, while a user maynotice a relatively brief pause in the video call, the user may not beaware of a call drop, and does not have to take action to proactivelyreestablish the video call following network transition. Such exampleembodiments accordingly provide for an improved user experience.

These and other embodiments are discussed below with reference to FIGS.1-6. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these Figures is forexplanatory purposes only and should not be construed as limiting.

FIG. 1 illustrates an example wireless communication system 100 inaccordance with some example embodiments. The system 100 can include awireless communication device 102, which can establish a video call witha remote communication device 104. By way of non-limiting example, thewireless communication device 102 can be a cellular phone, such as asmart phone device, a tablet computing device, a laptop computingdevice, or other computing device that can be configured forcompatibility with multiple cellular RATs. In some example embodiments,the wireless communication device 102 can be configured to connect toboth a first cellular network 106 and a second cellular network, such aslegacy cellular network 108.

The remote communication device 104 can be embodied as any device thatcan be configured to engage in a video call over a network connection,including, for example, a video phone, a cellular phone, a tabletcomputing device, a laptop computing device, a desktop computer, orother computing device. In some example embodiments, the remotecommunication device 104 can be embodied as a second wirelesscommunication device 102. The remote communication device 104 can beconfigured to use any access technology to access a network to engage ina video call and/or other communication session with the wirelesscommunication device 102. By way of non-limiting example, the remotecommunication device 104 of some example embodiments may be configuredto use a cellular technology, WLAN access technology, and/or otherwireless communications technology to access a network and engage in acommunication session with the wireless communication device 102. As afurther example, in some embodiments, the remote communication device104 may use a wireline connection, such as a digital subscriber line(DSL), cable internet, and/or other wireline network connection and/orother wireless communications technology to access a network and engagein a communication session with the wireless communication device 102

The first cellular network 106 can, for example, be a network that cansupport packet switched (PS) data transmission for a video call,including PS video data transmission and voice over Internet Protocol(VoIP) transmission and/or other PS technique for transmission of audiodata for the video call. As a non-limiting example, the first cellularnetwork 106 can be a fourth generation (4G) cellular network, such as a4G network implementing an LTE technology, such as an LTE network, anLTE-Advanced (LTE-A) network, and/or the like, which can support bothpacket switched video data transmission and voice over LTE (VoLTE)transmission of audio data for a video call. However, it will beappreciated that the first cellular network 106 of some embodiments canimplement some other existing and/or future-developed cellularnetworking technology, such as various fifth generation (5G) and beyondcellular networking technologies, capable of supporting PS datatransmission of both video and audio data for a video call.

The legacy cellular network 108 can be any network having a circuitswitched (CS) domain. By way of non-limiting example, the legacycellular network 108 can be a third generation (3G) network, such as aWideband Code Division Multiple Access (WCDMA) or other Universal MobileTelecommunications System (UMTS) network, such as a Time DivisionSynchronous Code Division Multiple Access (TD-SCDMA) network. As afurther example, the legacy cellular network 106 can be a CDMA2000network, such as a 1xRTT network, or other network standardized by theThird Generation Partnership Project 2 (3GPP2) that supports a CSdomain. As another example, the legacy cellular network can be a secondgeneration (2G) network such as a Global System for MobileCommunications (GSM) network.

As will be described further herein below, the wireless communicationdevice 102 and remote communication device 104 can have an establishedvideo call over the first cellular network 106. The video call can, forexample, be supported by a video call application, such as, by way ofnon-limiting example, Apple® FaceTime®, which can be implemented on thewireless communication device 102 and/or on the remote communicationdevice 104. A connection quality of a connection between the wirelesscommunication device 102 and the first cellular network 106 can degrade,such as due to mobility of the wireless communication device 102. As aresult of the degradation in connection quality, the wirelesscommunication device 102 can transition to the legacy cellular network108. For example, degradation of the connection quality may reach apoint at which the connection quality is less than a thresholdconnection quality that may be defined for measurement event reporting,reselection, handover, and/or other action that may result in a wirelesscommunication device transitioning between networks. In accordance withsome example embodiments described further herein below, a new videocall session can be established on the legacy cellular network 108 sothat the video call can be continued after the wireless communicationdevice 102 has transitioned to the legacy cellular network 108.

FIG. 2 illustrates a block diagram of an apparatus 200 that can beimplemented on a wireless communication device 102 and/or on a remotecommunication device 104 in accordance with some example embodiments. Inthis regard, when implemented on a computing device, such as wirelesscommunication device 102, apparatus 200 can enable the computing deviceto operate within the system 100 in accordance with one or more exampleembodiments. It will be appreciated that the components, devices orelements illustrated in and described with respect to FIG. 2 below maynot be mandatory and thus some may be omitted in certain embodiments.Additionally, some embodiments can include further or differentcomponents, devices or elements beyond those illustrated in anddescribed with respect to FIG. 2.

In some example embodiments, the apparatus 200 can include processingcircuitry 210 that is configurable to perform actions in accordance withone or more example embodiments disclosed herein. In this regard, theprocessing circuitry 210 can be configured to perform and/or controlperformance of one or more functionalities of the apparatus 200 (e.g.,of the wireless communication device 102) in accordance with variousexample embodiments, and thus can provide means for performingfunctionalities of the apparatus 200 in accordance with various exampleembodiments. The processing circuitry 210 can be configured to performdata processing, application execution and/or other processing andmanagement services according to one or more example embodiments.

In some embodiments, the apparatus 200 or a portion(s) or component(s)thereof, such as the processing circuitry 210, can include one or morechipsets, which can each include one or more chips. The processingcircuitry 210 and/or one or more further components of the apparatus 200can therefore, in some instances, be configured to implement anembodiment on a chipset. In some example embodiments in which one ormore components of the apparatus 200 are embodied as a chipset, thechipset can be capable of enabling a computing device to operate in thesystem 100 when implemented on or otherwise operably coupled to thecomputing device. Thus, for example, one or more components of theapparatus 200 can provide a chipset configured to enable a computingdevice to operate over the first cellular network 106 and/or legacycellular network 108.

In some example embodiments, the processing circuitry 210 can include aprocessor 212 and, in some embodiments, such as that illustrated in FIG.2, can further include memory 214. The processing circuitry 210 can bein communication with or otherwise control a transceiver(s) 216, userinterface 218, and/or video call manager 220.

The processor 212 can be embodied in a variety of forms. For example,the processor 212 can be embodied as various hardware-based processingmeans such as a microprocessor, a coprocessor, a controller or variousother computing or processing devices including integrated circuits suchas, for example, an ASIC (application specific integrated circuit), anFPGA (field programmable gate array), some combination thereof, or thelike. Although illustrated as a single processor, it will be appreciatedthat the processor 212 can comprise a plurality of processors. Inembodiments including a plurality of processors, the plurality ofprocessors can be in operative communication with each other and can becollectively configured to perform one or more functionalities of theapparatus 200 as described herein. In some example embodiments, theprocessor 212 can be configured to execute instructions that can bestored in the memory 214 or that can be otherwise accessible to theprocessor 212. As such, whether configured by hardware or by acombination of hardware and software, the processor 212 capable ofperforming operations according to various embodiments while configuredaccordingly.

In some example embodiments, the memory 214 can include one or morememory devices. Memory 214 can include fixed and/or removable memorydevices. In some embodiments, the memory 214 can provide anon-transitory computer-readable storage medium that can store computerprogram instructions that can be executed by the processor 212. In thisregard, the memory 214 can be configured to store information, data,applications, instructions and/or the like for enabling the apparatus200 to carry out various functions in accordance with one or moreexample embodiments. In some embodiments, the memory 214 can be incommunication with one or more of the processor 212, transceiver(s) 216,user interface 218, or video call manager 220 via a bus (or buses) forpassing information among components of the apparatus 200.

The apparatus 200 can further include transceiver(s) 216. Thetransceiver(s) 216 can enable the apparatus 200 to send wireless signalsto and receive signals from one or more cellular networks, such as thefirst cellular network 106 and/or the legacy cellular network 108. Assuch, the transceiver(s) 216 can be configured to support any type ofcellular or other wireless communication technology that may beimplemented by the first cellular network 106 and/or the legacy cellularnetwork 108. In some example embodiments, the transceiver(s) 216 caninclude a single transceiver configured to enable a device, such as thewireless communication device 102 to connect to both the first cellularnetwork 106 and the legacy cellular network 108. Alternatively, in someexample embodiments, the transceiver(s) 216 can include a firsttransceiver configured to enable a device to connect to the firstcellular network 106 and a second transceiver configured to enable thewireless communication device 102 to connect to the legacy cellularnetwork 108.

The apparatus 200 can additionally include a user interface 218. Theuser interface 218 can be in communication with the processor 212 toreceive an indication of a user input and/or to provide an audible,visual, mechanical, or other output to a user. As such, the userinterface 116 may include, for example, a keyboard, a mouse, a joystick,a display, a touch screen display, a microphone, a speaker, a camera,and/or other input/output mechanisms. For example, the user interface218 can include a display on which video for a video call can bedisplayed. As another example, the user interface 218 can include acamera configured to capture video for a video call.

The apparatus 200 can further include a video call manager 220. Thevideo call manager 220 can be embodied as various means, such ascircuitry, hardware, a computer program product including a computerreadable medium (for example, the memory 214) storing computer readableprogram instructions that are executable by a processing device (forexample, the processor 212), or some combination thereof. In someembodiments, the processor 212 (or the processing circuitry 210) caninclude, or otherwise control the video call manager 220. The video callmanager 220 can be configured to manage or otherwise supporttransitioning a video call between networks in accordance with one ormore example embodiments.

FIG. 3 illustrates a flowchart of operations that can be performed by awireless communication device 102 in accordance with an example methodfor transitioning a video call to the legacy cellular network 108according to some example embodiments. One or more of processingcircuitry 210, processor 212, memory 214, transceiver(s) 216, userinterface 218, or video call manager 220 can, for example, provide meansfor performing the operations illustrated in and described with respectto FIG. 3.

Operation 300 can include the wireless communication device 102participating in an ongoing video call with the remote communicationdevice 104 via a first video call session while connected to the firstcellular network 106. The first video call session may have beenestablished over the first cellular network 106. The video call can, forexample, be supported by a video call application, such as, by way ofnon-limiting example, Apple® FaceTime®, which can be implemented on thewireless communication device 102 and/or on the remote communicationdevice 104. The video call can include a video stream (e.g., a PS videostream) that can be carried over a first bearer on the first cellularnetwork 106 and an audio stream (e.g., a PS audio stream) that can becarried over a second bearer on the first cellular network 106. Thebearer carrying the audio stream can, for example, be a QCI1 bearer orother bearer, which can provide a guaranteed quality of service forsupporting PS voice transmission. In some example embodiments in whichthe first cellular network 106 is an LTE network (e.g., a networkimplementing LTE, LTE-A, and/or other LTE technology) that supportsVoLTE, the audio stream can be a VoLTE audio stream and the bearercarrying the audio stream can be a VoLTE bearer. For example, in somescenarios, such as embodiments in which both the wireless communicationdevice 102 and the remote communication device 104 are connected to anLTE network, the audio stream can be provided via end-to-end VoLTE. Insome such embodiments in which the audio stream is a VoLTE audio stream,the video call can comprise a VoLTE call with video for the video callbeing carried by a separate bearer and added on top of the VoLTE call.

Operation 310 can include the wireless communication device 102determining a degradation of a connection quality of the first cellularnetwork 106. For example, in some embodiments, determination of thedegradation can include determining that a connection quality for thefirst cellular network 106 has dropped below a threshold connectionquality. In this regard, the threshold connection quality can be athreshold, such as can be defined by the wireless communication device102 and/or by the first cellular network 106, for measurement eventreporting, reselection, handover, and/or other action that may triggerthe wireless communication device 102 to transition between networks.

The determination of operation 310 can be made based at least in part onmeasurements of the connection to the first cellular network 106 thatcan be made by the wireless communication device 102. The measuredconnection quality can be any measurable connection quality metric thatcan be indicative of a connection quality including, for example,received signal strength indicator (RSSI), reference signal receivedpower (RSRP), reference signal received quality (RSRQ), and/or the like.

The wireless communication device 102 and/or the first cellular network106 can decide to transition the wireless communication device 102 tothe legacy cellular network 108 in response to the degradation of theconnection quality of the first cellular network 106. Operation 320 canaccordingly include the wireless communication device 102 transitioningto the legacy cellular network 108 in response to the degradation inconnection quality.

In some embodiments, the first cellular network 106 may not support amechanism, such as single radio voice call continuity (SRVCC), fortransferring VoLTE and/or other PS voice stream to the legacy cellularnetwork 108. Accordingly, network coordinated transitioning (e.g.,handover) of the ongoing video call from the first cellular network 106to the legacy cellular network 108 may not be supported by the firstcellular network 106. As such, the original video call sessionestablished on the first cellular network 106 can be dropped by thenetwork and the remote communication device 104 can receive a sessioninitiation protocol (SIP) BYE message as a result of the wirelesscommunication device 102 transitioning to the legacy cellular network108.

The wireless communication device 102 of some example embodiments can beconfigured to take action to quickly establish a new replacement videocall session that can be presented to a user of the wirelesscommunication device 102 and/or the remote communication device 104 in amanner that can reduce disruption to the user(s) and provide a betteruser experience. In some example embodiments, the wireless communicationdevice 102 can be configured to send a signal (e.g., an in band signal)and/or other indication to the remote communication device 104indicating that the wireless communication device 102 is going totransition to a new network prior to performing operation 320. In suchexample embodiments, a video call application that can be implemented onthe remote communication device 104 can receive the signal and canindicate to a user of the remote communication device 104 that the videocall is still active even if the connection drops as a result of thewireless communication device 102 transitioning to the legacy cellularnetwork 108 for at least a predefined period of time to allow thewireless communication device 102 to establish a new video call sessionon the legacy cellular network 108 in a manner that can be transparentto a user of the remote communication device 104.

A user interface, such as a display of the user interface 218, in whichthe video call can be presented on the wireless communication device 102can likewise indicate to a user of the wireless communication device 102that the video call is still ongoing during the network transitionprocess until a new video call session can be established on the legacycellular network 108. Additionally or alternatively, in some exampleembodiments, such as that illustrated in and described below withrespect to FIG. 5, the wireless communication device 102 and/or remotecommunication device 104 can implement timers (e.g., guard timers) suchthat if an air interface connection is dropped by either end, such ascan result from the wireless communication device 102 transitioning tothe legacy cellular network 108, the video call user interfaces on thewireless communication device 102 and remote communication device 104can continue to indicate that the video call is active and give thewireless communication device 102 time (e.g., until timer expiry) tocomplete the transition to the legacy cellular network 108 and establisha new video call session on the legacy cellular network 108 beforeindicating to an end user(s) that the video call has been dropped.

Operation 330 can include the wireless communication device 102establishing a second video call session with the remote communicationdevice 104 on the legacy cellular network 108. For example, the secondvideo call session can be automatically established (e.g., in thebackground) without requiring a user of the wireless communicationdevice 102 to initiate a new session or alerting the user of the calldrop via the user interface. In establishing the second video callsession, an audio and video path to support the video call can beestablished between the wireless communication device 102 and remotecommunication device 104 over the legacy cellular network 108.

As indicated by operation 340, the wireless communication device 102 canprovide an indication via the user interface 218 that the video call isongoing while performing operations 320 and 330. Accordingly, while theuser may notice a brief interruption in the video call, the user may notbe aware of a call drop, and does not have to take action to proactivelyreestablish the video call following network transition.

Operation 350 can include the wireless communication device 102 usingthe second video call session to continue the video call on the legacycellular network 108. The second video call session can thus essentiallyreplace the original video call session from the first cellular network106. In this regard, users of the wireless communication device 102and/or remote communication device 104 may not be alerted that theoriginal call session had been dropped or that a new call session hasbeen initiated. Instead, based on the indication that can be providedattendant to performance of operation 340 in accordance with someexample embodiments, the video call can appear to continue to the usersas a single video call session with, perhaps, only a brief interruptionduring the network transition period and the time taken to establish anew video call session. As discussed above and as illustrated in anddescribed below with respect to FIG. 5, guard timers can be used by thewireless communication device 102 and/or remote communication device 104in some example embodiments in case re-establishment on the legacycellular network 106 fails so that notification may be provided to theusers of a call drop if the second video call session is notsuccessfully established within a defined period of time.

It will be appreciated that the methodology illustrated and describedwith respect to FIG. 3 can be applied mutatis mutandis to any networktransition that can be undergone by a wireless communication deviceparticipating in a video call, and thus can be applied in any situationin which network coordinated handover of an ongoing video call is notsupported. For example, if a video call is on an LTE network supportingVoLTE with the audio for the call in a dedicated audio stream carriedvia VoLTE, such as on a QC1 bearer, and the video carried in a separatevideo stream, and the wireless communication device 102 moves to an LTEnetwork that does not support VoLTE, the methodology described withrespect to FIG. 3 can be used to re-establish and continue the videocall on the LTE network that does not support VoLTE as a data call. As afurther example, if the wireless communication device 102 transitionsback to the first cellular network 106 from the legacy cellular network108, the methodology described with respect to FIG. 3 can be used tore-establish and continue the video call on the first cellular network106.

FIG. 4 illustrates a flowchart of operations that can be performed by awireless communication device in accordance with another example methodfor transitioning a video call between networks according to someexample embodiments. In this regard, FIG. 4 illustrates application ofthe methodology illustrated in and described with respect to FIG. 4 to amore generalized cellular network transition. Thus, for example, FIG. 4can include transitioning between a first LTE network supporting VoLTEand a second network that does not support VoLTE, transitioning from thelegacy cellular network 108 to the first cellular network 106, and/orother network transition. One or more of processing circuitry 210,processor 212, memory 214, transceiver(s) 216, user interface 218, orvideo call manager 220 can, for example, provide means for performingthe operations illustrated in and described with respect to FIG. 4.

Operation 400 can include a wireless communication device, such aswireless communication device 102, participating in a video call withparticipating in a video call with a remote communication device via afirst video call session established over a first cellular network. Inthis regard, operation 400 can correspond to a generalized embodiment ofoperation 300. The type of bearer arrangement that may be used for thevideo call can vary depending on a radio access technology (RAT) and/orother configuration of the cellular network.

Operation 410 can include the wireless communication device determininga degradation of a connection quality of the first cellular network. Asdiscussed with respect to operation 310, determination of thedegradation maybe based on a measurement(s) of the first cellularnetwork. In some embodiments, determination of the degradation mayinclude determining that a measured connection quality is less than athreshold connection quality, such as can be defined for measurementevent reporting, reselection, handover, and/or other action that maytrigger a wireless communication device to transition between networks.

The wireless communication device 102 and/or the first cellular network106 can decide to transition the wireless communication device 102 tothe legacy cellular network 108 in response to the degradation of theconnection quality of the first cellular network 106. Operation 320 canaccordingly include the wireless communication device 102 transitioningto the legacy cellular network 108 in response to the degradation inconnection quality.

Operation 420 can include the wireless communication devicetransitioning to the second cellular network in response to thedegradation of the connection quality of the first cellular network. Thefirst cellular network and/or second cellular network may not support amechanism for handing over the video call. For example, in instances inwhich the first cellular network is an LTE network supporting VoLTE, thesecond cellular network is an LTE network that does not support VoLTE,and an audio stream for the video call on the first cellular network isa VoLTE audio stream, transition of the video call to the secondcellular network may not be supported by the first cellular networkand/or the second cellular network. Accordingly, the first video callsession can be dropped as a result of the network transition. As such,the methodology of FIG. 3 may be used to establish a second video callsession as a data call carrying both video and audio for the video callon the LTE network that does not support VoLTE.

Operation 430 can include the wireless communication device establishing(e.g., automatically in the background) a second video call session withthe remote communication device on the second cellular network. Asillustrated by operation 440, the wireless communication device canprovide an indication via the user interface that the video call isongoing while transitioning to the second cellular network andestablishing the second video call session. Accordingly, while the usermay notice a brief interruption in the video call, the user may not beaware of a call drop, and does not have to take action to proactivelyreestablish the video call following network transition. Operation 450can include the wireless communication device using the second videocall session to continue the video call on the second cellular network.

FIG. 5 illustrates a flowchart of operations that can be performed by awireless communication device, such as wireless communication device102, in accordance with an example method for controlling user interfaceindications when transitioning a video call according to some exampleembodiments. More particularly, FIG. 5 illustrates an example of someembodiments of the methods of FIGS. 3 and 4 in which a guard timer canbe used. One or more of processing circuitry 210, processor 212, memory214, transceiver(s) 216, user interface 218, or video call manager 220can, for example, provide means for performing the operationsillustrated in and described with respect to FIG. 5.

Operation 500 can include the wireless communication deviceparticipating in a video call with a remote communication device via afirst video call session established over a first cellular network. Inthis regard, operation 500 can, for example, correspond to an embodimentof operation 300 and/or operation 400.

The wireless communication device can determine a degradation of theconnection quality of the first cellular network, such as described withrespect to operations 310 and 410. Operation 510 can, in turn, includethe wireless communication device setting a timer and transitioning to asecond cellular network in response to degradation of the connectionquality of the first cellular network. The first video call session canbe dropped as a result of the network transition.

Operation 520 can include the wireless communication device attemptingto establish (e.g., automatically in the background) a second video callsession with the remote communication device on the second cellularnetwork. Operation 530 can include the wireless communication deviceproviding an indication via the user interface that the video call isongoing while transitioning to the second cellular network andestablishing the second video call session. In this regard, operation530 can, for example, correspond to an embodiment of operation 340and/or operation 440.

Operation 540 can include the wireless communication device determiningif the second video call session has been successfully established onthe second cellular network. In an instance in which the second videocall session has been successfully established, the method can proceedto operation 550, which can include using the second video call sessionto continue the video call on the second cellular network, and themethod can terminate. In this regard, operation 550 can, for example,correspond to an embodiment of operation 350 and/or operation 450.

If, however, the second video call session has not been successfullyestablished, the method can instead proceed to operation 560, which caninclude determining if the timer set in operation 510 has expired. Ifthe timer has not expired, the wireless communication device cancontinue to attempt to establish the second video call session(operation 520) and provide an indication via the user interface thatthe video call is ongoing (operation 530) until the second video callsession is successfully established or until the timer expires. If it isdetermined at operation 560 that the timer has expired, the method canproceed to operation 570, which can include the wireless communicationdevice providing an indication via the user interface that the videocall has been dropped.

FIG. 6 illustrates a flowchart of operations that can be performed by acommunication device, such as remote communication device 104, inresponse to another device, such as wireless communication device 102,transitioning between networks during a video call according to someexample embodiments. In this regard, FIG. 6 illustrates operations thatcan be performed by a communication device participating in a video callwith wireless communication device 102 when wireless communicationdevice 102 performs one or more of the methods of FIGS. 3-5 inaccordance with some example embodiments.

Operation 600 can include a first communication device participating ina video call with a second communication device. Operation 610 caninclude the first communication device determining that the secondcommunication device is transitioning between networks. For example, insome embodiments, the second communication device can send an indicationthat it is transitioning between networks. As another example, in someembodiments, if the air interface is dropped and/or there is anotherinterruption in the video call without interruption in the networkconnection of the first communication device, the first communicationdevice can be configured to assume for at least a guard period of timethat the interruption is due to a network transition by the secondcommunication device.

Operation 620 can include the first communication device providing anindication via the user interface that the video call is ongoing whilewaiting for establishment of a new video call session by the secondcommunication device. Operation 630 can include the first communicationdevice continuing the video call after establishment of the new videocall session. Accordingly, while a user of the first communicationdevice may notice brief interruption in the video call, the user may notbe aware of a call drop. However, in embodiments in which the firstcommunication device implements a guard timer, if the new video callsession is not established before expiry of the timer, the firstcommunication device may provide an indication that the video call hasbeen dropped.

The various aspects, embodiments, implementations or features of thedescribed embodiments can be used separately or in any combination.Various aspects of the described embodiments can be implemented bysoftware, hardware or a combination of hardware and software. Thedescribed embodiments can also be embodied as a computer readable medium(or mediums) storing computer readable code including instructions thatcan be performed by one or more computing devices. The computer readablemedium may be associated with any data storage device that can storedata which can thereafter be read by a computer system. Examples of thecomputer readable medium include read-only memory, random-access memory,CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices.The computer readable medium can also be distributed overnetwork-coupled computer systems so that the computer readable code maybe stored and executed in a distributed fashion.

In the foregoing detailed description, reference was made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific embodiments in accordancewith the described embodiments. Although these embodiments are describedin sufficient detail to enable one skilled in the art to practice thedescribed embodiments, it is understood that these examples are notlimiting; such that other embodiments may be used, and changes may bemade without departing from the spirit and scope of the describedembodiments. For example, it will be appreciated that the ordering ofoperations illustrated in the flowcharts is non-limiting, such that theordering of two or more operations illustrated in and described withrespect to a flowchart can be changed in accordance with some exampleembodiments. As another example, it will be appreciated that in someembodiments, one or more operations illustrated in and described withrespect to a flowchart can be optional, and can be omitted.

Further, the foregoing description, for purposes of explanation, usedspecific nomenclature to provide a thorough understanding of thedescribed embodiments. However, it will be apparent to one skilled inthe art that the specific details are not required in order to practicethe described embodiments. Thus, the foregoing descriptions of specificembodiments are presented for purposes of illustration and description.The description of and examples disclosed with respect to theembodiments presented in the foregoing description are provided solelyto add context and aid in the understanding of the describedembodiments. The description is not intended to be exhaustive or tolimit the described embodiments to the precise forms disclosed. It willbe apparent to one of ordinary skill in the art that many modifications,alternative applications, and variations are possible in view of theabove teachings. In this regard, one of ordinary skill in the art willreadily appreciate that the described embodiments may be practicedwithout some or all of these specific details. Further, in someinstances, well known process steps have not been described in detail inorder to avoid unnecessarily obscuring the described embodiments.

What is claimed is:
 1. A method for transitioning a video call to alegacy cellular network, the method comprising a wireless communicationdevice: participating in a video call with a remote communication devicevia a first video call session established over a connection between thewireless communication device and a Long Term Evolution (LTE) network,the first video call session comprising a packet switched video streamcarried over a first bearer and a voice over LTE (VoLTE) audio streamcarried over a second bearer; determining that a measured connectionquality of the LTE network is less than a threshold connection quality;transitioning to a legacy cellular network having a circuit switcheddomain in response to determining that the measured connection qualityof the LTE network is less than the threshold connection quality;establishing a second video call session with the remote communicationdevice on the legacy cellular network in response to transitioning tothe legacy cellular network; providing an indication via a userinterface that the video call is ongoing while transitioning to thelegacy cellular network and establishing the second video call session;and using the second video call session to continue the video call onthe legacy cellular network.
 2. The method of claim 1, furthercomprising the wireless communication device sending an indication tothe remote communication device that the wireless communication deviceis transitioning between networks prior to transitioning to the legacycellular network.
 3. The method of claim 1, further comprising thewireless communication device: setting a timer in response todetermining that the measured connection quality of the LTE network isless than the threshold connection quality; and providing an indicationvia the user interface that the video call has been dropped in aninstance in which the second video call session is not established priorto expiry of the timer.
 4. The method of claim 1, wherein the LTEnetwork does not support single radio voice call continuity (SRVCC) fortransferring the VoLTE audio stream to the legacy cellular network. 5.The method of claim 1, wherein the first video call session is droppedby the LTE network.
 6. The method of claim 1, wherein the measuredconnection quality comprises one or more of a received signal strengthindicator (RSSI) of the LTE network, a reference signal received power(RSRP) of the LTE network, or a reference signal received quality (RSRQ)of the LTE network.
 7. The method of claim 1, wherein the legacycellular network comprises one of a Wideband Code Division MultipleAccess (WCDMA) network, Universal Mobile Telecommunications System(UMTS) network, Time Division Synchronous Code Division Multiple Access(TD-SCDMA) network, CDMA2000 network, or Global System for MobileCommunications (GSM) network.
 8. A wireless communication devicecomprising at least one transceiver, the at least one transceiverconfigured to send wireless signals to and receive wireless signals froma first cellular network and a legacy cellular network; and processingcircuitry coupled with the at least one transceiver, the processingcircuitry configured to control the wireless communication device to atleast: participate in a video call with a remote communication devicevia a first video call session established over a connection between thewireless communication device and the first cellular network, the firstvideo call session comprising a packet switched video stream carriedover a first bearer and a packet switched audio stream carried over asecond bearer; determine a degradation in connection quality of thefirst cellular network; transition to the legacy cellular network havinga circuit switched domain in response to the degradation in connectionquality of the first cellular network; establish a second video callsession with the remote communication device on the legacy cellularnetwork in response to transitioning to the legacy cellular network;provide an indication via a user interface that the video call isongoing while transitioning to the legacy cellular network andestablishing the second video call session; and use the second videocall session to continue the video call on the legacy cellular network.9. The wireless communication device of claim 8, wherein the firstcellular network is a Long Term Evolution (LTE) network, and wherein thesecond bearer is a voice over LTE (VoLTE) bearer.
 10. The wirelesscommunication device of claim 8, wherein the processing circuitry isfurther configured to control the wireless communication device todetermine the degradation in connection quality of the first cellularnetwork at least in part by controlling the wireless communicationdevice to determine that a measured connection quality of the firstcellular network is less than a threshold connection quality.
 11. Thewireless communication device of claim 8, wherein the processingcircuitry is further configured to control the wireless communicationdevice to send an indication to the remote communication device that thewireless communication device is transitioning between networks prior totransitioning to the legacy cellular network.
 12. The wirelesscommunication device of claim 8, wherein the processing circuitry isfurther configured to control the wireless communication device to: seta timer in response to the degradation in connection quality of thefirst cellular network; and provide an indication via the user interfacethat the video call has been dropped in an instance in which the secondvideo call session is not established prior to expiry of the timer. 13.The wireless communication device of claim 8, wherein the first cellularnetwork does not support transferring the packet switched audio streamto the legacy cellular network.
 14. A non-transitory computer readablestorage medium having computer program code stored thereon, the computerprogram code comprising program code, which, when executed by one ormore processors implemented on a wireless communication device, isconfigured to cause the wireless communication device to perform amethod comprising: participating in a video call with a remotecommunication device via a first video call session established over aconnection between the wireless communication device and a firstcellular network; determining a degradation in connection quality of thefirst cellular network; transitioning to a second cellular network inresponse to the degradation in connection quality of the first cellularnetwork; establishing a second video call session with the remotecommunication device on the second cellular network in response totransitioning to the second cellular network; providing an indicationvia a user interface that the video call is ongoing while transitioningto the second cellular network and establishing the second video callsession; and using the second video call session to continue the videocall on the second cellular network.
 15. The non-transitory computerreadable storage medium of claim 14, wherein the first video callsession comprises a packet switched video stream carried over a firstbearer and a packet switched audio stream carried over a second bearer,and wherein the second cellular network is a legacy cellular networkhaving a circuit switched domain.
 16. The non-transitory computerreadable storage medium of claim 15, wherein the first cellular networkis a Long Term Evolution (LTE) network, and wherein the second bearer isa voice over LTE (VoLTE) bearer.
 17. The non-transitory computerreadable storage medium of claim 14, wherein: the first cellular networkis a Long Term Evolution (LTE) network supporting voice over LTE(VoLTE); the first video call session comprises a packet switched videostream carried over a first bearer and a VoLTE audio stream carried overa second bearer; and the second cellular network is an LTE network thatdoes not support VoLTE.
 18. The non-transitory computer readable storagemedium of claim 14, wherein the method further comprises: sending anindication to the remote communication device that the wirelesscommunication device is transitioning between networks prior totransitioning to the second cellular network.
 19. The non-transitorycomputer readable storage medium of claim 14, wherein the method furthercomprises: setting a timer in response to the degradation in connectionquality of the first cellular network; and providing an indication viathe user interface that the video call has been dropped in an instancein which the second video call session is not established prior toexpiry of the timer.
 20. The non-transitory computer readable storagemedium of claim 14, wherein determining the degradation in connectionquality of the first cellular network comprises determining that ameasured connection quality of the first cellular network is less than athreshold connection quality.